On Level 3, when I have a crash and click to tow truck to clean up the mess, it just highlights the rails, it doesn't clean up the mess which means I have to restart the game because I can't get around the crash. Has anyone experienced this? Is there a fix?

Without seeing the layout of rails it's difficult to say if it was a bug. Sometimes trains crash where two tracks cross and it isn't obvious which track you need to clean up. If it's going about an individual rail track, it is a bug.

It does seem to be at intersections. I clicked again on the tow truck and carefully clicked one train. It highlighted a section of track the crashed train was on. I clicked on the tow truck again and carefully clicked the other train. It highlighted the other track. It doesn't do any more than highlight a section of track. I have a screen shot but can't seem to post it here.

Screenshot could be helpful. You can send it to support@belightsoft.com together with the link to this topic, or upload it to any file sharing server and post here the link. To show an image here, place the link between the "img" and "/img" tags as in this example: